Insulating rocker panel

[g6civcx]

There is a big empty space in the rocker panel under the door.

What's the best thing to fill this space? Jute felt? polyfoam? expanding foam? window insulation?

[ranger240]

s13 hatches have sunroof drain tubes that end in there.. re-route those if youre going the expanding foam route or something

[g6civcx]

s13 hatches have sunroof drain tubes that end in there.. re-route those if youre going the expanding foam route or something

Fortunately I don't buy anything with sunroofs. Thanks for the tip though.

[Devil Man]

make sure you get the right foam... you want to have structual foam that has density with closed cell foam.

google structual foam and you will find it. you dont want to use the shit from home depot its not right.

[GSXRJJordan]

Like we discussed in the audio thread, the pro's I talked to said not to try to fill it with anything. If you're doing it for sound deadening purposes, you don't need to fill the space, just damp the panels and put some noise barrier (like that Damplifier Pro I used, or Dynamat Dynaliner/Dynapad) in there.

If you're doing it for chassis stiffening, there's no foam that'll harden enough to make an appreciable difference.

Open cell foam retains moisture, so that's out.

High density closed-cell structural foam is an effective weather barrier, but doesn't do anything for noise or strength.

It seems counter-intuitive, but I still think the best thing is to not fill the area.

[g6civcx]

I remember reading in SCC a LONG time ago, like back in 97-98 where they filled the frame of a 300ZX with some kind of foam and they said it made the car stiffer.

I remember what you said. Thanks for the comments.

I went ahead with the Mr. Gasket GMuff spray and just coated the inside of the rear fender with that stuff. I can't tell if it makes any difference but it was easy to do and cheap.

I'm going to try what Russ and some upholstery books said and stuff it full of jute felt.

Since the rocker panel tends to get wet I think I may just leave it alone and coat the interior with Dynamat like we talked about.

Thanks.